Furnace charging apparatus

ABSTRACT

An apparatus for charging particulate burden material into a shaft furnace, such as a blast furnace, having a generally vertical axis. Several individual port means are spaced around the axis and mounted on the upper portion of the furnace above two superposed furnace bells in superposed stationary hoppers. Each of the port means has an upwardly open mouth, and individual valve means for closing the port means gas tight and for opening it independently of other port means so it can provide a flow of material into the furnace. Two externally supported non-rotatable independently laterally reciprocable chutes are mounted above the port means. Each chute has a plurality of lower discharge openings each of which is positionable over and alignable with the mouth of selected port means by proper reciprocable movement of the chute, to discharge material into the mouth so that material will pass from the chute into the furnace when the port means is open; and each chute has a corresponding number of upper openings adapted to receive charge material deposited in the chute and discharge it through the discharge opening that is aligned with an open port means. A stationary hopper is mounted above each chute to receive charge material from suitable material supply means such as a skip car or conveyor, and discharge it into the proper chute opening.

United States Patent 1191 Glover Dec. 25, 1973 FURNACE CHARGINGAPPARATUS [75] Inventor:

[73] Assignee: Arthur 'G. McKee & Company,

Cleveland, Ohio [22] Filed: Mar. 1, 1972 [21] Appl. No.: 230,606

Warren E. Glover, Lakewood, Ohio Primary Examiner-Robert G. SheridanAttorney-Paul S. Sessions et al.

[ 5 7 ABSTRACT An apparatus for charging'particulate burden materialinto a shaft furnace, such as a blast furnace, having a generallyvertical axis. Several individual port means are spaced around the axisand mounted on the upper portion of the furnace above two superposedfurnace bells in superposed stationary hoppers. Each of the port meanshas an upwardly open mouth, and individual valve means for closing theport means gas tight and for opening it independently of other portmeans so it can provide a flow of material into the furnace. Twoexternally supported non-rotatable independently laterally reciprocablechutes are mounted above the port means. Each chute has a plurality oflower discharge openings each of which is positionable over andalignable with the mouth of selected port means by proper reciprocablemovement of the chute, to discharge material into the mouth so thatmaterial will pass from the chute into the furnace when the port meansis open; and each chute has a corresponding number of upper openingsadapted to receive charge material deposited in the chute and dischargeit through the discharge opening that is aligned with an open portmeans. A stationary hopper is mounted above each chute to receive chargematerial from suitable material supply means such as a skip car orconveyor, and discharge it into the proper chute opening.

27 Claims, 8 Drawing Figures FURNACE CHARGING APPARATUS DISCLOSURE OFTHE INVENTION Field of the Invention desired amounts and distribution ofthe material while 0 preventing gas leakage from the furnace, even ifthe furnace operates under severe conditions as occur when the furnacehas high internal gas pressure and is of large diameter.

BACKGROUND OF THE INVENTION To achieve greater production and increasedefficiencies and economies in blast furnace construction and operation,recent blast furnace designs have trended toward the use ofsubstantially higher internal top pressures than have been heretoforecommon.

In new furnaces being designed or built, top pressures range as high aspounds per square inch, hearth diameters range up to 50 feet or more,and iron outputs up to 6,000 tons per day or higher.

Moreover, there is a considerable demand for conversion of olderfurnaces to enable them to operate at considerably higher top pressuresfor greater efficiencies and outputs. Such conversions in generalrequire the provision of top apparatus for charging materials andsealing against escape of gas that is different from the apparatusheretofore used. However, it is desirable that the new furnace topapparatus not exceed the height of the old replaced apparatus, to reducethe cost of the conversion by avoiding the necessity of replacing orrepositioning other top equipment such a downcomers, bleeder valves, andthe like.

These factors of high gas pressures and high productions, whenaccompanied by factors of large size in new furnaces or heightlimitations on converted older furnaces, impose severe problems in thedesign and operation of the charging apparatus of such furnaces topermit the rapid charging of required large quantities of burdenmaterial for high production and the desired distribution of burdenmaterial over the furnace crosssectional area of the furnace forefficient high volume production of high quality iron, while preventingleakage of the gas at high pressures.

DISCUSSION OF PRIOR ART,

For example, these factors cause substantial problems with the type ofcharging apparatus heretofore widely used, wherein a hopper the bottomof which is closed by a small bell is rotatably mounted above a largerhopper the bottom of which is closed by a large bell, the rotatablesmall bell hopper being sealed at its circumference to prevent internalfurnace gases from leaking out. When higher gas pressures are used,tendencies toward leakage are intensified in this structure. The gasleakage problem is also accentuated if in large capacity furnaces thediameter of the small bell hopper is enlarged to permit handling atsuitable high rates of the large amounts of burden material that must becharged into the furnace.

Various proposals have been made to overcome these problems, mostlyinvolving eliminating rotation of the small bell hopper. In one designdeveloped recently, both the large bell and small bell hoppers arenon-rotatable and respectively closed by non-rotatable large and smallbells, and a rotatable chute is mounted inside the small bell hopper todeposit burden material on the small bell at the desired lateralposition. Above the chute and in the top of the small bell hopper, thereare one or more valves that can be closed to seal furnace gas, and canbe opened to permit burden material to be discharged into the chutewhile it is rotating or while it is stationary to discharge at a desiredlocation on the small bell. Stationary hopper systems are used above thevalves.

In such apparatus, the chute is supported and driven from a rod thatsurrounds the two bell rods. Since triple supporting rods are thereforerequired, one of which must be rotatable, a complicated constructionresults that is not only expensive'to build but also is subject tosubstantial maintenance problems. There is danger of breakdowns becauseof heat, dust or burden material which can cause jamming of the chute ina position where it cannot be moved to accomplish the desired depositingof the material at different locations around the furnace interior, sothat the furnace cannot be successfully operated. Moreover, the chutecan be reached only with great difficulty for maintenance repair orreplacement, since it is inside the hopper. Furthermore, the design doesnot readily lend itself to the conversion of older furnaces to high toppressure operation.

In another recently developed design, there are stationarysuperposedsmall and large bell hoppers, and another stationary hopper, fixed abovethe small bell hopper, that has branched discharging ports at itsbottom. Each of these discharging ports is closed by a material cutoffvalve and by a gas cutoff valve. Each discharging port opens into thefixed small bell hopper when its valves are open. A rotatable chute ismounted within the upper portion of this branched upper hopper. Inoperation, burden material from the rotatable chute, usually while thechute is rotating, is deposited in the branches of the upper hopper,being supported by the material cutoff valves. At the appropriate time,both the material cutoff and gas cutoff valves of a selected hopperbranch and port are opened to permit material to discharge into thesmall bell hopper to deposit material on the small bell at the desiredlocation.

While in this design the rotatable chute may be supported and rotated bymeans located externally of any bell hopper the fact that the materialis deposited inside of a hopper and held there by several cutoff valvesimposes difficulties and disadvantages, as because of complications inproviding and operating several material cutoff valves and because thesevalves can jam due to the material supported by them. Moreover, at leastthe lower end of the chute is in the branched hopper at all times andcould become jammed or clogged by material in the hopper. If the chuteshould jam, clog, or otherwise become damaged, it is a difficult,timeconsuming and costly operation to get access to that portion of thechute for corrective action. Moreover, the operation of the materialcutoff valves and gas cutoff valves must be carefully coordinated toprevent burden material discharging from the chute from striking anddamaging or destroying the gas cutoff valve if the material cutoff valveshould be opened in a particular branch port before the gas cutoffvalve. Furthermore, this design does not readily lend itself to theconversion of older furnaces to high top pressure operation.

SUMMARY OF THE INVENTION It is an object of the invention to provideapparatus for charging particulate material into a shaft furnace such asa blast furnace, that will operate efficiently in small or largefurnaces to charge desired quantities of particulate burden materialinto the furnace in any of a wide range of distribution patterns in thefurnace, while the furnace is operating under gas pressures as high asany contemplated at present or the foreseeable future. Another object isthe provision of such apparatus which can be built to fit heightlimitations of older furnaces that are to be converted to high toppressure operation. It is a further object of the invention to avoid theproblems and disadvantages of prior art apparatus such as thosedescribed above.

The present invention provides apparatus for charging particulate burdenmaterial into a shaft furnace having an upper furnace portion with agenerally vertical axis, which apparatus includes a plurality of meansproviding ports mounted on the upper furnace portion and spaced aroundthe axis, each of the port means having an upwardly open mouth, valvemeans for closing each port means gas tight and for opening each of theport means independently of other means to permit flow of materialthrough the port means unimpeded by the valve means and an externallysupported and driven chute reciprocably mounted above the port means.The chute has a plurality of lower discharge openings each adapted to bemoved over the mouth ofa selected port means and to discharge burdenmaterial into the mouth of such port means so that the material willpass by gravity from the chute into the furnace, preferably into a bellhopper such as a small bell hopper above a large bell hopper, when thegas sealing valve of such port is open; the chute also has a pluralityof upper openings each adapted to receive burden material thatdischarges through a lower chute opening while it is aligned with aselected port means. The apparatus also has means for depositing burdenmaterial into the upper opening of the chute that communicates with thelower opening aligned with its selected port means. The chute is notenclosed in any hopper, and is supported and reciprocated externally ofany hopper so the chute is readily accessible for maintenance and repairand can be free of any tendency to be jammed or clogged by chargematerial in a hopper. Preferably, a plurality of chutes are used, suchas two chutes reciprocable in parallel paths, each of which chutessupplies material to half the port means of the furnace.

There is no rotatable hopper that can provide gas sealing problems.There is no chute contained within any hopper that prevents access tothe chute only with difficulty or that can retain material that will jamor clog the chute. The valve means in the furnace port means need onlybe used for sealing against escape of gas. There are no valves in thefurnace port means that are required to hold material discharged fromthe chute, since the material entering the chute only discharges througha selected port means into the furnace when the port means is open.

Consequently, apparatus can be made more simply than prior apparatuses.The problems of sealing against high gas pressures are simplifiedbecause there is no member such as a hopper of large circumference thatmust be sealed against gas leakage, but several considerably smallervalves able to withstand readily any force caused by high furnacepressure. By providing a proper number of port means preferably at leastfour, and proper cycling of the position of each chute, the desireddistributions of material within the furnace can be readily achievedeven though the furnace has a large cross section and diameter.

Moreover, apparatus embodying the invention can be made of sufficientlylow overall height so it can be installed on existing furnaces toreplace existing charging equipment without major alterations to othertop structure.

BRIEF DESCRIPTION OF THE DRAWINGS These and other advantages of theinvention will become apparent from the following description inconnection with the accompanying drawings in which:

FIG. 1 is a vertical section through the upper portion of a blastfurnace, generally along line l--l of FIG. 2, illustrating a preferredtype of furnace charging apparatus embodying the invention and utilizingskip car material supply means;

FIG. 2 is a view from line 22 of FIG. 1 and to the same scale; I

FIG. 3 is a plan section along line 3-3 of FIG. 1 but to a larger scale;

FIG. 4 is a somewhat diagrammatic perspective view to a larger scale,showing means for actuating the gas sealing valve of one of the portmeans;

FIGS. 5, 6 and 7 are plan views, generally along the section line fromwhich FIG. 3 is taken but to the scale of FIGS. 1 and 2 and moreschematically shown than FIG. 3, showing three separate lateralpositions of each of the two chutes of the illustrated embodiment, andhow the chutes when so positioned can deliver charge material to all sixof the ports of the illustrated embodiment, each chute deliveringmaterial to one port when it is in one of the positions; and

FIG. 8 is a view generally corresponding to FIG. 1 but to a smallerscale, showing another embodiment in which material is delivered to tworeciprocable chutes by a belt.

DESCRIPTION OF PREFERRED EMBODIMENTS In the apparatus of FIG. 1, a blastfurnace l of otherwise known construction has an upper portion 2comprising a known stationary large bell hopper 3 the bottom opening ofwhich can be opened and closed by large bell 4, and above hopper 3another stationary small bell hopper 5 having a bottom opening thatopens into the top of hopper 3 and can be opened and closed by smallbell 6, the bells being symmetrical about axis A of the furnace.

Neither of hoppers 3 and 5 rotate. Large bell 4 is supported, lifted andlowered by a bell ,rod 7 in known manner. Small bell 6 is supported,lifted and lowered in known manner by a tubular bell rod 8 slidablysurrounding bell rod 7 in known manner. The bells do not rotate whilethey close their respective hoppers; however, if desired, either or bothmay be rotated when lowered in hopper opening position, as to equalizewear. Known means, not shown, are provided for actuating the bell rods 7and 8 to raise and lower their bells as required, and for rotating thebells if desired when they are lowered.

The top wall 11 closing the small bell hopper 5 has a tubular portion 12surrounding tubular bell rod 8 and extending upwardly to a locationgenerally above the charging apparatus. The axes of the rods and portion12 coincide with axis A. Toprevent escape of furnace gas past the bellrods 7 and 8 and tubular portion'l2, sealing means 13 operates betweentubular portion 12 and reciprocable small bell rod 8, and sealing means14 operates between bell rod 8 and bell rod 7 of the large bell. Sincethese sealing means may be conventional, no further description isrequired.

Two side-by-side upper fixed hoppers l5, 16 (FIGS. 1, 2, 3) supported byframe members at a suitable distance above top wall 11 of the furnace,are adapted to receive particulate burden material to be charged intothe furnace, each from a suitable source of supply such as one of a pairof conventional skip cars 19 alternately traveling up and down tracks20.

Preferably, as shown in FIG. 3, each hopper l5 and 16 has an upperopening 22 that is generally rectangular in plan and is shaped andadapted to receive burden material from one of the adjacent skip cars19. The lower portion 23 of each illustrated hopper l5, l6 slopesdownwardly and inwardly todefine (FIG. 3) a fixed generally rectangularbottom opening 24 at a fixed predetermined lateral location relative tothe upper furnace portion. Adjacent upper portions of the hoppers flareoutwardly and are joined at ridge 25 and to tubular portion 12 toprevent entrance of charge material there.

A plurality of port means 26 are disposed around the axis A and fixedgas-tight to the top wall 11 of the small bell hopper 5 of the furnace.Preferably there are at least four, and desirably six as in theillustrated embodiment, of port means to insure good distribution ofburden material in the furnace. Each port means comprises a housing 27(FIG. 1) having an upwardly open outwardly flared or divergent mouth 28,the mouths preferably all being of the same size and shape andpreferably circular in cross section. The upper edges of all the portmeans lie in the same horizontal plane, and preferably they are alsoequiangularly and equidistantly spaced around axis A (FIG. 3). Each portmeans 26 also includes a gassealing valve 29 (FIGS. 1, 4) mounted inhousing 27 and adapted to close the lower end of a passage 31 the upperend of which terminates in mouth 28.

In the illustrated embodiment (FIG. 4) each valve 29 comprises astationary valve seat at the lower end of passage 31 and an upwardlyconvex movable closure member 32 that is pivotally mounted by lug 33 onan offset curved arm 34 that is fixed to a horizontal rotatable shaft 35extending to the outside of housing 27 of the port means but sealed byconventional means against gas leakage from the housing. While the shaftmay be rotated as required to open and close the valve 29 by variousknown means, that shown comprises a gear segment 36 rigidly mounted onshaft 35 and engaging a gear 37 that is rotated as required by a motor38 which may be a conventional type energized as required by known meansrequiring no description. If desired, the valve seat 31 or the uppersurface of closure member 32 may be covered in whole or in part wherethey meet with sealing or gasket material such as synthetic rubber toaid in providing a tight gas seal; an annular layer 39 of such materialis shown on closure member 32 in FIG. 4. Use of such sealing materialthat might otherwise be damaged by substantial heat is made possiblebecause the valves 29 are so located that they are not exposed toharmful heat.

The arrangement, including the offset curved arm 34 is such that when avalve of a port means is in the closed position as shown in full linesin FIG. 1 it closes passage 31 and hence the mouth 28 of the port meansand provides a gas-tight seal even at high pressures in the furnace, theforce on closure member 32 exerted by the gas pressure aiding in keepingthe valve closed gastight; and when the arm 34 is turned to the valveopen position shown in broken lines in FIG. 1, all portions of the valvecompletely clear the passage and permit an uninterrupted and unimpededflow of burden material through the port means into small bell hopper 5;and any sealing layer 39 is not contacted or damaged by the chargematerial. Each valve is operable independently of the other valves, andthe valves can be made so that when all valves are closed, even if thepressure in the small bell hopper is equivalent to a high furnacepressure, there is no gas leakage.

The embodiment of FIGS. 1 to 3 also includes two reciprocable chutes 41and 42 respectively located below stationary hoppers l5 and I6 and abovethe port means 26. Each chute is adapted to discharge burden materialfrom its associated hopper 15 or 16 into a selected one of three portmeans 26 that are served by the chute. Each chute 41, 42 is rigidlymounted in a movable frame 43 supported by wheels 44 traveling onparallel rails 45 located at the sides of the chute and supported byportion 46 of a furnace frame structure. Each chute can therefore movehorizontally on its rails in a fixed linear path; the paths for bothchutes in the illustrated apparatus being straight and parallel. Eachchute is moved as required to the desired position in its path by afluid operated cylinder 47 fixed to frame portion 46 and connected tochute frame 43 by piston rod 48. Each fluid cylinder 47 is powered andcontrolled to move its chute as and when required by suitableconventional means not shown.

Chute 41 comprises (FIGS. 1, 3) three downwardly extending chuteportions 51, 52 and 53, respectively having lower openings 54, 55 and 56lying essentially in a common horizontal plane at the bottom of thechute and top openings 57, 58 and 59 lying essentially in a commonhorizontal plane at the top of the chute. Each chute portion is inclinedas a whole from the ver' tical, and designed so that when the upperopening of any chute portion is brought under the lower opening 24 ofthe fixed hopper 15, the corresponding lower opening of that chuteportion is aligned with the mouth 28 of a preselected one of the portmeans 26 predetermined to have burden material pass into it from suchlower chute opening-The lower openings of all the chute portions areshaped, and the flared upper ends of the mouths 28 are shaped and sized,so that material can discharge into the open mouth of the port meanswith no loss of material passing from hopper 15 to chute 41 and into theport means. Therefore, all lower chute openings 54, 55, 56 preferablyare of identical circular cross section, and all of the flared upperends of mouths 28 are circular and somewhat larger in cross section.

As apparent from FIGS. 3, 5-7, portion 51 of reciprocable chute 41discharges burden material from stationary hopper 15 into only the portmeans 26 that for convenience is designated P-l when upper opening 57 ofchute portion 51 is aligned with bottom opening 24 of hopper 15 (FIG.5); chute portion 52 of chute 41 discharges material only into the portmeans designated as P-2 when top opening 58 of portion 52 is alignedwith bottom opening 24 of hopper 15 (FIG. 6); and chute portion 53discharges material from hopper 15 into only the port means designatedas P-3 when chute top opening 59 is aligned with bottom opening 24 ofhopper 15 FIG. 7). i

The other chute means 42 is identically shaped, including inclined chuteportions 51, 52' and 53 respectively having bottom openings 54, 55' and56 and top openings 57', 58 and 59. Its chute portions are adapted todischarge burden material received by them from hopper 16 into specificones of the port means 26 designated as P-4, P-5 and P-6 when the upperopening of the chute portion is aligned with the bottom opening '24 of hopper 16, as is apparent from FIG. 3 in conjunction with FIGS. 5, 6 and7.

In view of the above described features of design and relationship ofthe parts, by proper reciprocation of the chutes 41 and 42 relative tothe furnace 1 and to each other, it is possible to achieve variouscycles of operation for introducing burden material deposited in thestationary hoppers l5 and 16 into various ones of the port means 26designated as P-1 to P-6 inclusive in the illustrated embodiment."

One illustrative mode of operation can be understood in connection withFIGS. 5 to 7. In this mode of operation, chute 41, while empty of burdenmaterial and while no burden is being deposited in stationary hopper bya skip car 19, is moved by actuation of its fluid cylinder 47 so upperopening 57 of chute portion 51 is directly beneath bottom opening 24 ofhopper 15 and so bottom opening 54 of chute portion 51 is directly abovethe flared open mouth 28 of the port means 26 that is designated as P-l,as shown in FIGS. 3 and 5.

Simultaneously, or at any suitable time, chute 42 is moved by itscylinder 47 to a position so that its upper opening 57' of chute portion51' is below bottom opening 24 of stationary hopper 16 and bottomopening 54' of chute portion 51 is directly over the flared open mouth28 of the port means designated as P-4, which is diametrically oppositeport means P-l. The valves 29 of all port means are closed and both thelarge and small bells are in their hopper closing positions during thistime. During or before this time small bell hopper 5 has been filled bysuitable known means with clean gas such as steam, clean blast furnacegas, or nitrogen at a pressure approximately equal to even slightlyexceeding the gas pressure in the remainder of the furnace. The largebell hopper 3 contains gas at furnace pressure.

Thereafter, the gas pressure in the small bell hopper 5 is relieved bysuitable known means to atmospheric pressure and gas seal valves 29 ofthe port means designated as P-1 and P-4 are opened and burden materialfrom the skip cars 19 is discharged into hoppers l5 and 16, from whichthe material passes by gravity through the chute portions 51 and 5.1 ofchutes 41 and 42 into the small bell hopper 5 where it is retained bythe closed hell 6.

Thereafter, the gas seal valves 29 of port means P-1 and P4 are closedand the small bell hopper is pressurized in known manner with clean gas,after which the small bell is lowered to discharge materials from thesmall bell hopper into hopper 3 onto large bell 4. The above steps maybe carried out one or more times as desired or required by the chargingcycle. In the usual process, several skip carloads of burden materialwill be deposited on the large bell.

After the desired amount of burden material has been deposited on thelarge bell, and after the small bell has been raised to its upperclosing position and the small bell hopper pressurized with clean gas ifdesired, the large bell is droppedas shown in broken lines in FIG. 1, todeposit the material in the furnace. During all of this time the largebell hopper 3 has contained gas under the pressure of the furnace gasbelow the large bell. This gas is introduced in the large bell hopper byconventional means not shown. This cycle with the chutes in thisposition may be repeated as often as desired.

Thereafter during or after dropping the large bell, and while no burdenmaterial is deposited into the upper hoppers 15 and 16, while the gasvalves 29 of all port means are closed gas tight the chutes 41 and 42while empty are moved to the positions illustrated by FIG. 6 in whichtheir middle chute portions 52 and 52' are located so their upperopenings 58 and 58' are aligned with the bottom openings 24 of thestationary hoppers 15 and 16, and their lower openings 55 and 55' aredirectly over the flared mouths 28 of the port means 26 designated asP-2 and P-5. During or before this time the small bell hopper has beenpressurized with clean gas, and the large bell hopper contains gas atfurnace pressure. The gas pressure in the small bell hopper is thenrelieved to atmospheric pressure, gas seal valves 29 of the port'meansdesignated as P-2 and P-S are opened, and burden material from skip cars19 is discharged into hoppers l5 and 16 from which it passes throughchute portions 52 and 52 of chutes 41 and 42 through the mouths of portmeans P-2 and P-S into the furnace where the material is retained by theclosed small bell 6. Thereafter the gas seal valves are closed and smallbell hopper 5 is pressurized with clean gas after which small bell 6 islowered to discharge its material onto large bell 4 in hopper 3. Theabove steps may be carried out one or more times as desired or requiredby the charging cycle. After the desired amount of charge material hasbeen deposited on the large bell, and after the small bell has beenraised to its hopper closing position and the small bell hopperpressurized with clean gas if desired, the large bell is dropped todeposit burden material in the furnace. This cycle with the chutes inthis position may be repeated as often as desired.

Thereafter, during or after dropping of the large bell, and while nocharge material is being deposited into upper hoppers 15 and 16, andwhile gas seal valves of all port means are closed, the chutes 41 and 42are then moved to the positions shown in FIG. 7 in which the upperopenings 59 and 59 of chute portions 53 and 53' are located directlybelow the openings 24 in the bottoms of hoppers 15 and 16 and the loweropenings 56 and 56 of these same chute portions are directly over theflared mouths of the port means 26 that are designated as P-3 and P-6.After relieving of gas pressure in the small bell hopper while the smallbell hopper is closed by the small bell, the valve means 29 of portmeans P-3 and P-6 are opened and burden material is deposited by skipcars into hoppers 15 and 16 from which it passes through chute portions53 and S3 of chutes 41 and 42 and through the mouths of port means P-3and P-S into the small bell hopper 5 of the furnace. After one or moreloads from each skip car are thus deposited, the gas valves are closed,the small bell hopper is repressurized with clean gas and the small bellthen is lowered to drop material onto the large bell that closes thelarge bell hopper; this portion of the cycle is repeated until thedesired amount of material is deposited on the large bell. Thereafter,after all the valve means in all port means are closed, the small bellhopper pressurized with clean gas to match the pressure in the largebell hopper which contains gas at furnace pressure, the large bell isthen dropped to deposit its charge material in the furnace. This cyclewith the chutes so positioned may be repeated as often as desired.

The cycle described above may be repeated during the furnace campaignwith all port means in the indicated sequence to achieve the desireddistribution of desired charge material in the furnace. In the abovecycle, moreover charging occurs through two diametrically opposite portmeans and substantially simultaneously; this provides substantialsavings in time of charging, and in the amounts of clean gas used sincefewer number of refillings of the small bell hopper with clean gas arerequired; this also results in desirable distribution of charge materialon opposite sides of the furnace from diametrically opposite ports.

Of course, other modes of operation of the above described apparatus arepossible, including those in which either or both reciprocating chutesmove after each skip car load of material is deposited, or those inwhich more than one skip car load of material is deposited on the smallbell before it is dumped, or those in which each chute is moved whilethe other chute is stationary until each chute discharges materialthrough each of the several ports served by such chute.

ln all of these processes, advantages are also provided becausedifferences in, and duration of differences in, gas pressures above andbelow the bells are minimized, thus minimizing leakage of dust-laden gaspast the bells that could cause abrasion or wear of the bells andpossibilities of further leakage.

While in the embodiment described above material is deposited by skipcars into the upper hoppers and 16 and passes from such hoppers throughthe chutes to selected port means, it is possible to deposit material inthe upper hopper by other means.

FIG. 8 illustrates another embodiment in which burden material issupplied by a known type of belt conveyor assembly 61 in which belt 62passes around end pulley 63 located in housing 64. Burden material issupplied to the belt in known manner by known means. Burden materialdischarged from the belt into housing 64'passes to either-of twostationary hoppers 15a or 16a, depending on position of diverting valvemembers 65 and 66. In the illustrated embodiment each of the valvemembers 65 and 66 in each case is pivotally mounted at its upper end inan extended upper portion of one of the hoppers 15a and 16a andpivotally connected at its lower end to a common actuating rod 67adapted to be moved reciprocably as desired by a known type of fluidpowered cylinder 68. The arrangement is such that as shown in FIG. 8when hopper 15a is opened by valve member 65 to receive material fromthe belt 62, the other hopper 16a is closed by its valve member 66, andvice versa. The diverting valve members 65 and 66 thus divert thematerial that is supplied by the belt to either one of the stationaryhoppers 15a and 160 depending on the position of the diverting valvemembers, from which the material can pass through the suitablypositioned reciprocable chutes 41 and 42 to the desired ones of the portmeans 26 that are designated as P-l to P-6 inclusive. Chutes 41 and 42and the portions of the embodiment of H6. 8 below the chutes may beidentical with those of FIGS. 1 to 7 and need no further description,particularly since corresponding parts have identical referencecharacters in both embodiments.

If desired, the charging operation cycles described above in connectionwith FIGS. 4-7 may be used, or any other suitable cycle. The arrangementcan also be such that the belt 61 while running brings burden materialcontinuously, or discontinuously in slugs.

The present invention overcomes disadvantages of prior apparatus, someof which were discussed above, and makes possible efficient, effectiveand rapid charging of burden material in a desirable distribution in afurnace, even if the furnace has large capacity or large diameter.Moreover, apparatus of the invention can be effectively used in furnacesoperating at high gas pressures, with little if any gas leakage.

The chutes 41 and 42 may be relatively shallow and moved laterallyparallel to the plane of the mouths of the port means as in theillustrated embodiments; for these reasons apparatus embodying theinvention can be readily applied to older furnaces without increasing,and indeed in some cases with substantial reduction in, the height ofthe furnace top apparatus. The overall height of the furnace thereforeneed not be increased beyond its original height,'and other portions ofthe furnace top such as downcomers, bleeder valves, or roofs need not beexpensively modified or replaced.

Furthermore, apparatus embodying the invention makes possible modes ofoperation in which the amounts of dirty gas discharged into theatmosphere as well as the amounts of clean gas used for equalizingpressures discharged into the atmosphere can be greatly reduced, becausethe volume of the small bell hopper used for pressure equalization byclean gas and discharge of gas into the atmosphere is much smaller thanthe volume of the large bell hopper that is usually used for thesepurposes in conventional practice.

Prevention of gas leakage is simplified because there is no rotatinghopper or other part of large diameter that must be circumferentiallysealed against gas leakage, and because each of the gas seal valves 29is small and located away from-the heat and can be sealed by rubberlikeor other sealing material. Moreover, when a gas seal valve is closed,the pressure of the gas below tends to keep it closed. The gas sealvalves are located in the illustrated embodiment so that they are notsubjected to harmful heat that can cause deterioration.

Construction is simplified and less costly, especially in largefurnaces, than with many prior designs of apparatus intended for similarservice. Little if any abrasion of bells occurs because there is littleif any leakage of dust-laden furnace gas between any bell and its seatwhen the bell is closed. Indeed, in an operation as described above,there is no need for the large bell to be gastight, since pressures arethe same on both sides of the bell so abrasion from gas leakage past thelarge bell is eliminated. The large bell will therefore have a muchlonger life than in conventional furnaces, which is a very importantadvantage since maintenance costs are reduced and production losses forlarge bell maintenance or replacement are greatly reduced.

Furthermore, as indicated, the reciprocable chutes may be supported anddriven entirely from outside of the apparatus and no part of the chutesneed be in a hopper, so that problems of maintenance or repair aregreatly minimized because of easy accessability to the chutes.

Moreover, in emergency, the gas seal valves can be repaired withouttaking the furnace off pressure, since the valves are easily accessibleand quickly replaced and since the furnace can be operated if necessarywith the valves 29 open in a manner akin to conventional practice inwhich the large bell is used as a gas valve.

Various modifications apparent to those skilled in the art, in additionto those indicated, may be made in the apparatus and methods indicatedabove, and changes may be made with respect to the features disclosed,provided that the elements set forth in any of the following claims orthe equivalents of such, be employed.

What is claimed is:' r

1. Apparatus for charging particulate charge material into a shaftfurnace comprising an upper furnace portion; a plurality of port means,each having an upwardly open mouth, spaced laterally about .the top ofsaid furnace portion; valve means for closing each of said port means ingas sealing relation and for opening each of said port meansindependently of other port means; a chute mounted above said port meansfor lateral reciprocatory movement in a substantially straight lateralpath, said chute having a lower discharge opening adapted to belaterally moved to close proximity to the mouth of a selected port-means so that charge material can pass from said chute into saidfurnace when said port means is open, said chute having an upper openingadapted to receive charge material deposited therein that is dischargedthrough said lower opening, said chute being supported and havingessentially its entire lower portion thereof located externally of anyhopper adapted to contain charge material; and means for depositingcharge materialinto the upper opening of said chute.

2. Apparatus according to claim 1 comprising an upper hopper above saidchute adapted to discharge material from said hopper into the upperopening of said chute; and means for depositing charge material intosaid hopper.

3. The apparatus of claim 2 in which said means for discharging materialinto said upper hopper includes skip car means.

4. The apparatus of claim 2 in which said means for discharging materialinto said upper hopper comprises conveyor means; and which apparatuscomprises material cutoff means to prevent discharge of material fromsaid upper hopper until the lower opening of said chute is over themouth of a selected port means and the gas sealing valve means for saidport means is open.

5. The apparatus of claim 1 in which said means for discharging materialinto said chute comprises skip car means.

6. The apparatus of claim 1 in which said means for discharging materialinto said chute comprises con veyor means. I

7. The apparatus of claim 1 in which each of said valve means when openpermits unimpeded flow of material through said port means into saidfurnace.

8. The apparatus of claim 1' in which there are at least four of saidport means each having a mouth opening upwardly.

9. The apparatus of claim 1 in which there are six of said port meanseach having a mouth opening upwardly.

10. Apparatus for charging particulate charge material into a shaftfurnace comprising an upper furnace portion; a plurality of port means,each having an upwardly open mouth, spaced laterally about the top ofsaid furnace portion; valve means for closing each of said port means ingas sealing relation and for opening each of said port meansindependently of other port means; a chute mounted above said port meansfor lateral reciprocatory movement in a linear path, said chute having aplurality of lower discharge openings and an upper opening communicatingwith each of said lower openings, said lower openings being located sothat by said lateral movement of said chute each lower opening can bebrought into a position where it can discharge into the mouth of apredetermined selected one of said port means different from the otherport means,

.said chute being supported and'having essentially its entire lowerportion thereof located externally of any hopper adapted to containcharge material, means for imparting said lateral reciprocatory movementin said linear path to said chute; and means for depositing chargematerial into the upper opening of said chute when its associated loweropening is in a position where it can discharge into the mouth of apredetermined selected one of said port means.

1 l. The apparatus of claim 10 in which said chute has a plurality ofupper openings each of which communicates with only one ofsaid lowerdischarge openings, each of which upper openings is adapted to bepositioned so it is at a fixed predetermined lateral location relativeto said upper furnace portion when its associated lower dischargeopening is aligned in close proximity to the mouth of the selected portmeans into which it is to discharge; and in which said means fordepositing charge material into the upper opening of said chutedischarges charge material into an upper opening when it is at saidfixed predetermined location.

12. The apparatus of claim 11 in which said last mentioned meansincludes a hopper above said chute having a discharge opening at saidfixed predetermined lateral location.

13. The apparatus of claim 11 in which there are two of said chutes eachadapted to discharge material into predetermined ones of said pluralityof port means.

14. Apparatus for charging particulate charge material into ashaftfurnace comprising an upper furnace portion having a generallyvertical axis; a non-rotatable bell hopper having an open bottom and aclosed top wall; a bell adapted to open and close said bottom of saidhopper; a plurality of port means located around said axis and mountedon the top wall of said bell hopper, each of said port means having anupwardly open 'mouth; valve means for closing each of said port means ingas sealing relation and for opening each of said port meansindependently of other port means; a pair of chutes mounted above saidport means, one of each side of said axis, for reciprocating movement ina straight lateral path, the paths of movement of said chutes beinggenerally parallel, each of said chutes having a plurality of lowerdischarge openings each of which communicates with its own upper openingin said chute, said lower openings being arranged so that each can belocated over the mouth of a predetermined port means at one side of saidaxis and said upper openings being located so that when a lower openingis over its predetermined port means the upper opening in communicationwith it is at a fixed predetermined location at which it can receivecharge material, each of said lower discharge openings being adapted tobe aligned in close proximity to the mouth of its predetermined portmeans so that charge material introduced into the upper opening incommunication with the lower opening will pass from said chute into saidfurnace when said port means is open, and means for depositing materialinto each upper opening of said chute when it is in said predeterminedlocation.

15. Apparatus according to claim 14 comprising a fixed hopper above saidchute adapted to discharge material from said hopper into an upperopening of said chute at said predetermined location; and means fordepositing charge material into said hopper.

16. The apparatus of claim 14 in which said means for dischargingmaterial into said chute comprises skip car means.

17. The apparatus of claim 14 in which said means for dischargingmaterial into said chute comprises conveyor means.

18. The apparatus of claim 14 in which the lower portion of each of saidchutes includes a plurality of inclined chute portions each having alower discharge opening.

19. The apparatus of,claim 14 in which said port means are at least fourin number and equidistantly and equiangularly spaced around said axis,and each of said chutes is adapted to discharge charge material intohalf the number of said port means.

20. The apparatus of claim 18 in which there are six port means, andeach of said chutes has three lower discharge openings and three upperopenings.

21. The apparatus of claim 14 comprising nonrotatable hopper means abovesaid chutes having a discharge opening at said fixed predeterminedlocation to discharge charge material into an upper opening of saidchute when it is at said fixed predetermined location and means fordepositing charge material into said hopper.

22. The apparatus of claim 14, comprising a nonrotatable bell hopperbelow said first mentioned bell hopper and having an open bottom; and abell adapted to open and close said bottom of said hopper.

23. Apparatus for charging particulate charge material into a shaftfurnace comprising an upper furnace portion having a top wall; aplurality of port means laterally spaced on said top wall, each of saidport means having an upwardly open mouth; valve means for closing eachof said port means in gas sealing relation and for opening each of saidport means independently of other port means so that when said valvemeans is open charge material can flow into the mouth of the portmeans'and through the port means into said furnace; a plurality ofchutes mounted above said port means, each of said chutes beingsupported and driven in a lateral path independently of any other chuteand having essentially its entire lower portion thereof locatedexternally of any hopper adapted to contain charge material, each ofsaid chutes having a plurality of lower discharge openings adapted to bemoved laterally over the mouths of predetermined ones of said portmeans, each of said lower discharge openings being adapted to be alignedin close proximity to the mouth of a selected port means so that chargematerial can pass from said chute discharge opening into said furnacewhen said port means is open, said chute having an open top portionadapted to receive charge material deposited therein that can bedischarged through said lower discharge openings.

24. The apparatus of claim 22 in which each of said chutes has aplurality of upper openings each of which communicates with only one ofsaid lower discharge openings, and each of which upper openings isadapted to be positioned so it is at a fixed predetermined laterallocation relative to said upper furnace portion when its associatedlower discharge opening is aligned in close proximity to the mouth ofthe selected port means into which it is to discharge; and means fordischarging charge material into said upper opening when it is at saidfixed predetermined location.

25. The apparatus of claim 23 in which said furnace has a vertical axis,and in which said chutes comprise a pair of chutes mounted above saidport means one on each side of said axis, each of said chutes beingadapted to discharge charge material into at least one port means intowhich charge material cannot be discharged from the other chute.

26. Apparatus for charging particulate charge material into a furnacecomprising an upper furnace portion having a top wall; a plurality ofport means laterally spaced on said top wall, each ofsaid port meanshaving an upwardly open mouth; valve means for closing each of said portmeans in gas sealing relation and for opening each of said port meansindependently of other port means so that when said valve means is open,charge material can flow into the mouth of the port means and. throughthe port means into said furnace; a chute mounted above said furnace forreciprocatory movement in a lateral path, said chute having apermanently open lower discharge opening adapted to be laterally movedinto close proximity to the mouth of a selected port means so thatcharge material can pass from said chute into said furnace when saidport means is open, said chute having an upper opening adapted toreceive charge material disposed therein that is discharged through saidlower opening, said chute being supported and having essentially itsentire lower portion located externally of any hopper adapted to containcharge material; and means for depositing charge material into the upperopening of said chute only when its lower discharge opening associatedwith said upper opening is in close proximity to the mouth of a selectedport means so that charge material can pass from said chute into saidfurnace when said port means is open.

27. The apparatus of claim 26 comprising a plurality of chutes, eachmounted for reciprocatory movement in an independent lateral path, eachof said chutes being adapted to discharge charge material into at leastone port means into which material cannot be discharged from the otherchute.

1. Apparatus for charging particulate charge material into a shaftfurnace comprising an upper furnace portion; a plurality of port means,each having an upwardly open mouth, spaced laterally about the top ofsaid furnace portion; valve means for closing each of said port means ingas sealing relation and for opening each of said port meansindependently of other port means; a chute mounted above said port meansfor lateral reciprocatory movement in a substantially straight lateralpath, said chute having a lower discharge opening adapted to belaterally moved to close proximity to the mouth of a selected port meansso that charge material can pass from said chute into said furnace whensaid port means is open, said chute having an upper opening adapted toreceive charge material deposited therein that is discharged throughsaid lower opening, said chute being supported and having essentiallyits entire lower portion thereof located externally of any hopperadapted to contain charge material; and means for depositing chargematerial into the upper opening of said chute.
 2. Apparatus according toclaim 1 comprising an upper hopper above said chute adapted to dischargematerial from said hopper into the upper opening of said chute; andmeans for depositing charge material into said hopper.
 3. The apparatusof claim 2 in which said means for discharging material into said upperhopper includes skip car means.
 4. The apparatus of claim 2 in whichsaid means for discharging material into said upper hopper comprisesconveyor means; and which apparatus comprises material cutoff means toprevent discharge of material from said upper hopper until the loweropening of said chute is over the mouth of a selected port means and thegas sealing valve means for said port means is open.
 5. The apparatus ofclaim 1 in which said means for discharging material into said chutecomprises skip car means.
 6. The apparatus of claim 1 in which saidmeans for discharging material into said chute comprises conveyor means.7. The apparatus of claim 1 in which each of said valve means when openpermits unimpeded flow of material through said port means into saidfurnace.
 8. The apparatus of claim 1 in which there are at least four ofsaid port means each having a mouth opening upwardly.
 9. The apparatusof claim 1 in which there are six of said port means each having a mouthopening upwardly.
 10. Apparatus for charging particulate charge materialinto a shaft furnace comprising an upper furnace poRtion; a plurality ofport means, each having an upwardly open mouth, spaced laterally aboutthe top of said furnace portion; valve means for closing each of saidport means in gas sealing relation and for opening each of said portmeans independently of other port means; a chute mounted above said portmeans for lateral reciprocatory movement in a linear path, said chutehaving a plurality of lower discharge openings and an upper openingcommunicating with each of said lower openings, said lower openingsbeing located so that by said lateral movement of said chute each loweropening can be brought into a position where it can discharge into themouth of a predetermined selected one of said port means different fromthe other port means, said chute being supported and having essentiallyits entire lower portion thereof located externally of any hopperadapted to contain charge material, means for imparting said lateralreciprocatory movement in said linear path to said chute; and means fordepositing charge material into the upper opening of said chute when itsassociated lower opening is in a position where it can discharge intothe mouth of a predetermined selected one of said port means.
 11. Theapparatus of claim 10 in which said chute has a plurality of upperopenings each of which communicates with only one of said lowerdischarge openings, each of which upper openings is adapted to bepositioned so it is at a fixed predetermined lateral location relativeto said upper furnace portion when its associated lower dischargeopening is aligned in close proximity to the mouth of the selected portmeans into which it is to discharge; and in which said means fordepositing charge material into the upper opening of said chutedischarges charge material into an upper opening when it is at saidfixed predetermined location.
 12. The apparatus of claim 11 in whichsaid last mentioned means includes a hopper above said chute having adischarge opening at said fixed predetermined lateral location.
 13. Theapparatus of claim 11 in which there are two of said chutes each adaptedto discharge material into predetermined ones of said plurality of portmeans.
 14. Apparatus for charging particulate charge material into ashaft furnace comprising an upper furnace portion having a generallyvertical axis; a non-rotatable bell hopper having an open bottom and aclosed top wall; a bell adapted to open and close said bottom of saidhopper; a plurality of port means located around said axis and mountedon the top wall of said bell hopper, each of said port means having anupwardly open mouth; valve means for closing each of said port means ingas sealing relation and for opening each of said port meansindependently of other port means; a pair of chutes mounted above saidport means, one of each side of said axis, for reciprocating movement ina straight lateral path, the paths of movement of said chutes beinggenerally parallel, each of said chutes having a plurality of lowerdischarge openings each of which communicates with its own upper openingin said chute, said lower openings being arranged so that each can belocated over the mouth of a predetermined port means at one side of saidaxis and said upper openings being located so that when a lower openingis over its predetermined port means the upper opening in communicationwith it is at a fixed predetermined location at which it can receivecharge material, each of said lower discharge openings being adapted tobe aligned in close proximity to the mouth of its predetermined portmeans so that charge material introduced into the upper opening incommunication with the lower opening will pass from said chute into saidfurnace when said port means is open, and means for depositing materialinto each upper opening of said chute when it is in said predeterminedlocation.
 15. Apparatus according to claim 14 comprising a fixed hopperabove said chute adapted to discharge material from said hopper into anupper opening of said chute at saId predetermined location; and meansfor depositing charge material into said hopper.
 16. The apparatus ofclaim 14 in which said means for discharging material into said chutecomprises skip car means.
 17. The apparatus of claim 14 in which saidmeans for discharging material into said chute comprises conveyor means.18. The apparatus of claim 14 in which the lower portion of each of saidchutes includes a plurality of inclined chute portions each having alower discharge opening.
 19. The apparatus of claim 14 in which saidport means are at least four in number and equidistantly andequiangularly spaced around said axis, and each of said chutes isadapted to discharge charge material into half the number of said portmeans.
 20. The apparatus of claim 18 in which there are six port means,and each of said chutes has three lower discharge openings and threeupper openings.
 21. The apparatus of claim 14 comprising non-rotatablehopper means above said chutes having a discharge opening at said fixedpredetermined location to discharge charge material into an upperopening of said chute when it is at said fixed predetermined locationand means for depositing charge material into said hopper.
 22. Theapparatus of claim 14, comprising a non-rotatable bell hopper below saidfirst mentioned bell hopper and having an open bottom; and a belladapted to open and close said bottom of said hopper.
 23. Apparatus forcharging particulate charge material into a shaft furnace comprising anupper furnace portion having a top wall; a plurality of port meanslaterally spaced on said top wall, each of said port means having anupwardly open mouth; valve means for closing each of said port means ingas sealing relation and for opening each of said port meansindependently of other port means so that when said valve means is opencharge material can flow into the mouth of the port means and throughthe port means into said furnace; a plurality of chutes mounted abovesaid port means, each of said chutes being supported and driven in alateral path independently of any other chute and having essentially itsentire lower portion thereof located externally of any hopper adapted tocontain charge material, each of said chutes having a plurality of lowerdischarge openings adapted to be moved laterally over the mouths ofpredetermined ones of said port means, each of said lower dischargeopenings being adapted to be aligned in close proximity to the mouth ofa selected port means so that charge material can pass from said chutedischarge opening into said furnace when said port means is open, saidchute having an open top portion adapted to receive charge materialdeposited therein that can be discharged through said lower dischargeopenings.
 24. The apparatus of claim 22 in which each of said chutes hasa plurality of upper openings each of which communicates with only oneof said lower discharge openings, and each of which upper openings isadapted to be positioned so it is at a fixed predetermined laterallocation relative to said upper furnace portion when its associatedlower discharge opening is aligned in close proximity to the mouth ofthe selected port means into which it is to discharge; and means fordischarging charge material into said upper opening when it is at saidfixed predetermined location.
 25. The apparatus of claim 23 in whichsaid furnace has a vertical axis, and in which said chutes comprise apair of chutes mounted above said port means one on each side of saidaxis, each of said chutes being adapted to discharge charge materialinto at least one port means into which charge material cannot bedischarged from the other chute.
 26. Apparatus for charging particulatecharge material into a furnace comprising an upper furnace portionhaving a top wall; a plurality of port means laterally spaced on saidtop wall, each of said port means having an upwardly open mouth; valvemeans for closing each of said port means in gas sealing relation andfor opeNing each of said port means independently of other port means sothat when said valve means is open, charge material can flow into themouth of the port means and through the port means into said furnace; achute mounted above said furnace for reciprocatory movement in a lateralpath, said chute having a permanently open lower discharge openingadapted to be laterally moved into close proximity to the mouth of aselected port means so that charge material can pass from said chuteinto said furnace when said port means is open, said chute having anupper opening adapted to receive charge material disposed therein thatis discharged through said lower opening, said chute being supported andhaving essentially its entire lower portion located externally of anyhopper adapted to contain charge material; and means for depositingcharge material into the upper opening of said chute only when its lowerdischarge opening associated with said upper opening is in closeproximity to the mouth of a selected port means so that charge materialcan pass from said chute into said furnace when said port means is open.27. The apparatus of claim 26 comprising a plurality of chutes, eachmounted for reciprocatory movement in an independent lateral path, eachof said chutes being adapted to discharge charge material into at leastone port means into which material cannot be discharged from the otherchute.